Skin cancers are the most common cancer type in western world. Currently, between two to three million non-melanoma and 132,000 melanoma cases are reported globally each year (WHO). Melanoma is the most common cancer for young adults 25-29 years old. About 90 percent of non-melanoma skin cancers and 86 Lentigo Maligna (LM) is an early form of melanoma in which the malignant cells are confined to the tissue of origin, the epidermis, hence it is often reported as in situ melanoma. It occurs in sun damaged skin. Lentigo Maligna Melanoma (LMM) is diagnosed when the malignant melanoma cells have invaded into the dermis and deeper layers of skin. The prognosis for invasive LMM is poorer than in LM. Clinically LM cannot be differentiated from invasive LMM.
For both, LM and LMM, surgical removal is the first treatment. It is essential to remove all damaged skin cells, since even a few damaged cells left behind can launch cancer again. The borders of LM and LMM are often hard to define by eye due to subclinical extension of the lesion borders seen only in histopatholgical sampling. Often a re-excision is required.
No accurate in vivo methods currently exist to accurately identify the areas of tumor cell spread. Early accurate diagnosis will increase patients' survival and decrease cost of treatment dramatically.
State-of-the-art method utilized clinically is based examination lesions with dermato-scope. These devices are practically optical magnifiers which have from one to three different integrated illumination choices. These devices can be used together with normal digital cameras. This type of equipment acquires a high-resolution image with three wide spectral bands (red, green and blue).
Hyperspectral imaging offers accurate spatial and spectral information about imaged skin lesions. FIG. 1 illustrates a hyperspectral datacube. As seen in FIG. 1, a hyperspectral image contains from couple of dozen to thousands monochromatic images which are taken within a short period of time and from same location. A set 104 of images is typically called a hyperspectral data cube. These monochromatic images are taken at 70 different wavelengths. Thus, basically, every pixel in a hyperspectral image represents the intensity of light in a certain spot at a certain wavelength. A set of pixels trough hyperspectral data cube forms a spectrum 106.